Cdc6-Induced Conformational Changes in ORC Bound to Origin DNA Revealed by Cryo-Electron Microscopy

Sun, J., Kawakami, H., Zech, J., Speck, C., Stillman, B., Li, H. (March 2012) Cdc6-Induced Conformational Changes in ORC Bound to Origin DNA Revealed by Cryo-Electron Microscopy. Structure, 20 (3). pp. 534-544. ISSN 0969-2126

Abstract

Summary The eukaryotic origin recognition complex (ORC) interacts with and remodels origins of DNA replication prior to initiation in S phase. Here, we report a single-particle cryo-EM-derived structure of the supramolecular assembly comprising Saccharomyces cerevisiae ORC, the replication initiation factor Cdc6, and double-stranded ARS1 origin DNA in the presence of ATPγS. The six subunits of ORC are arranged as Orc1:Orc4:Orc5:Orc2:Orc3, with Orc6 binding to Orc2. Cdc6 binding changes the conformation of ORC, in particular reorienting the Orc1 N-terminal BAH domain. Segmentation of the 3D map of ORC-Cdc6 on DNA and docking with the crystal structure of the homologous archaeal Orc1/Cdc6 protein suggest an origin DNA binding model in which the DNA tracks along the interior surface of the crescent-like ORC. Thus, ORC bends and wraps the DNA. This model is consistent with the observation that binding of a single Cdc6 extends the ORC footprint on origin DNA from both ends.

Item Type:	Paper
Subjects:	bioinformatics > genomics and proteomics > genetics & nucleic acid processing bioinformatics > genomics and proteomics Investigative techniques and equipment bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification Investigative techniques and equipment > microscopy > electron microscopy bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > origin recognition complex bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types
CSHL Authors:	Stillman, Bruce W.
Communities:	CSHL labs > Stillman lab CSHL Cancer Center Program > Gene Regulation and Cell Proliferation
Highlight:	Stillman, Bruce W.
Depositing User:	Matt Covey
Date:	March 2012
Date Deposited:	18 Jan 2013 19:48
Last Modified:	20 Jun 2017 16:26
PMCID:	PMC3299985
Related URLs:	Publisher
URI:	https://repository.cshl.edu/id/eprint/27057

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